How to add custom author's bio to WordPress single post page

functions.php

/*
* Add custom contacts for WordPress user as we want user to have links to their Twitter, LinkedIn, etc accounts
*/
function worduoso_contactmethods( $contactmethods ) {
  $contactmethods['linkedin'] = 'Linked In'; // Add LinkedIn
  $contactmethods['twitter'] = 'Twitter'; // Add Twitter
  $contactmethods['facebook'] = 'Facebook'; // Add Facebook
  return $contactmethods;
}

add_filter('user_contactmethods','worduoso_contactmethods',10,1);

/*
* Optional: load font awesome to display icons for contact list
* you may use custom icons or text instead - just skip the following block.
* Also check if your theme already has font awesome to avoid double loading.
*/
function worduoso_scripts() {
    wp_enqueue_style( 'fontawesome', '//maxcdn.bootstrapcdn.com/font-awesome/4.4.0/css/font-awesome.min.css');
}

add_action( 'wp_enqueue_scripts', 'worduoso_scripts', 999);

single.php

<?php
/*
* This code should be added to single post template (single.php by default)
* we will display custom author's bio only if "description" is set for the user.
* I use (optional) markup for the person from https://schema.org in this code.
* Also I use FontAwesome to display icons for contact links, e.g. <i class="fa fa-desktop"></i>
*/
$description = get_the_author_meta("description");
$facebook = get_the_author_meta("facebook");
$twitter = get_the_author_meta("twitter");
$linkedin = get_the_author_meta("linkedin");
$website = get_the_author_meta("user_url");
?>
<div class="blog-author" itemprop="author" itemscope itemtype="http://schema.org/Person">
  <?php echo get_avatar( get_the_author_meta('ID'), 200); ?>
  <h3 itemprop="name"><?php echo get_the_author(); ?></h3>
  <p><?php echo $description; ?></p>
  <div class="blog-author-contacts">
    <?php if($website) { ?>
    <a itemprop="url" href="<?php echo $website; ?>"><i class="fa fa-desktop"></i></a>
    <?php } ?>
    <?php if($facebook) { ?>    
    <a itemprop="sameAs" href="<?php echo $facebook; ?>"><i class="fa fa-facebook"></i></a>
    <?php } ?>
    <?php if($twitter) { ?>        
    <a itemprop="sameAs" href="http://www.twitter.com/<?php echo $twitter; ?>"><i class="fa fa-twitter"></i></a>
    <?php } ?>
    <?php if($linkedin) { ?>            
    <a itemprop="sameAs" href="<?php echo $linkedin; ?>"><i class="fa fa-linkedin"></i></a>
    <?php } ?>
  </div>
</div>